A short synthesis of 4,5-methanochrysene and 6-oxo-7-oxabenzo[a]pyrene, two benzo[a]pyrene analogs

Lee‐Ruff, Edward; Kruk, Henry; Katz, Michael

doi:10.1021/jo00177a035

Cited by 19 publications

(4 citation statements)

References 7 publications

(13 reference statements)

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“…Both of these overreactions are plausible with regard to the known reactions of chrysene-6-carboxylic acid, which gives the corresponding pentagonal ketone upon dehydration in liquid HF and the corresponding intramolecular lactone upon irradiation in the presence of air and iodine. [27] The mass spectrum, with a dominant peak at 320.0836 Da that corresponds to [C 23 H 12 O 2 ] + , is in agreement with the lactone structure 17. As shown in Figure 1, the 1 H NMR spectrum of 17 has a singlet very far downfield at d = 9.92 ppm (compared with d = 9.02 ppm in the ester) because of the rigidly coplanar carbonyl (which is free to rotate in the butyl ester), and a doublet at d = 7.58 ppm, which is upfield of the triplets and is indicative of a proton next to a phenolic oxygen.…”

Section: Resultssupporting

confidence: 58%

Synthesis of Carboxy‐Functionalized Polycyclic Arenes by Oxidative Cyclizations of 2,3‐Diarylacrylates

et al. 2012

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The cyclization of esters of Perkin condensation products by oxidation with 2,3‐dichloro‐5,6‐dicyanobenzoquinone (DDQ) in the presence of MeSO3H is examined as a three‐step approach from arylacetic acids and aromatic aldehydes to functionalized condensed arenes. The method is limited to systems in which one or both of the two aryl moieties are more reactive than a phenyl group, such as 1‐naphthyl or, especially, 3‐thienyl. Alkoxycarbonyl derivatives of picene, benzo[c]chrysene, three isomeric phenanthrothiophenes, a naphthothiophene, and a benzodithiophene were obtained. The extension of this approach to multiple cyclizations and, thus, to extended partially condensed systems with multiple alkoxycarbonyl substituents appears promising with highly active precursors derived from 3‐thienylacetic acid. In this case, conjugated polymers made of short ribbon fragments linked by thiophene–thiophene single bonds appear conceivable. A bifunctional chrysenodithiophene was obtained from 1,5‐diformylnaphthalene, together with a highly unusual asymmetric dimer that contains a cyclohepta[de]naphthalene (pleiadiene) moiety.

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Section: Resultssupporting

confidence: 58%

Synthesis of Carboxy‐Functionalized Polycyclic Arenes by Oxidative Cyclizations of 2,3‐Diarylacrylates

et al. 2012

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“…30 Ahn and co-workers improved the synthetic method for preparation of benzo[g]coumarin and employed this new approach in fluorescence imaging. 31,32 Among coumarins p-expanded at positions 4 and 5, a large number of 4-oxa-pyren-5-one analogs have been studied, [33][34][35] including the naturally occurring alkaloid santiagonamine. 36 On the other hand, the synthesis and photophysical properties of analogous systems corresponding to the perylene skeleton have not been studied yet.…”

Section: Introductionmentioning

confidence: 99%

Vertically π-expanded coumarin – synthesis via the Scholl reaction and photophysical properties

Tasior

Deperasińska

Morawska

et al. 2014

Phys. Chem. Chem. Phys.

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A short and efficient access to a unique type of π-expanded coumarin is achieved. The strategic placement of naphthalene at the 4-position of coumarin allowed us to fuse these two moieties via aromatic dehydrogenation under Scholl conditions. The intriguing optical properties of this π-expanded coumarin are discussed on the basis of quantum chemical calculations. The fluorescence quantum yield (∼20%) is significantly higher than that obtained for the classical 7-hydroxycoumarin. The ratio of emission versus radiationless deactivation is governed by the following factors: decrease in the oscillator strength of the SS transition (vs. perylene), low yield of intersystem crossing and strong internal conversion originating from the activity of the number of vibronic states.

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“…Introduction of a methano-bridge into chrysene (→ 6 ) increases electrophilic reactivity while at the same time removing one of the bay regions. Various synthetic strategies have been devised to produce 6 in satisfactory yields for further studies. , In 6 , apart from the diol epoxide activation pathway, a new reactive site for DNA binding may be formed by enzymatic hydroxylation on the relatively acidic bridge position followed by esterification and cleavage to a carbocation …”

Section: Introductionmentioning

confidence: 99%

Stable Ion Studies of the Chrysene Skeleton. Protonation of Chrysene, 6-Halochrysenes, 6-Acetylchrysene, and 4H-Cyclopenta[def]chrysene: NMR Studies of Charge Distribution in Chrysenium Cations and AM1 Calculations

et al. 1997

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Chrysene (1), 6-fluorochrysene (2), 6-chlorochrysene (3), and 6-bromochrysene (4) are cleanly monoprotonated in FSO 3 H‚SbF 5 (ca. 10:1)/SO 2 ClF at the C-12 position. 6-Acetylchrysene (5) is CO-protonated in FSO 3 H/SO 2 ClF with significant charge delocalization into the chrysene and provides a model for a C-6-protonated chrysenium cation. 4H-Cyclopenta[def]chrysene (6) is protonated at C-5 (site of bromination and acetylation). The observed chrysenium (methanochrysenium) cations are those predicted by AM1 to have the lowest energies. The NMR characteristics of the resulting arenium ions are discussed and the ∆δ 13 Cs are compared with AM1 calculated changes in charges [∆q c ) q c (ion) -q c (neutral)]. Possible relationships between the charge delocalization path in chrysenium ions and metabolic activation of chrysenes by electrophilic pathways via the bay-region epoxide ring opening (f PAH-DNA adduct) are evaluated.

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A short synthesis of 4,5-methanochrysene and 6-oxo-7-oxabenzo[a]pyrene, two benzo[a]pyrene analogs

Abstract: Methylated polynuclear aromatic hydrocarbons are often more carcinogenic than the parent derivatives. It is known that the bay region methylated 5-methylchrysene (1) is a

Cited by 19 publications

References 7 publications

Synthesis of Carboxy‐Functionalized Polycyclic Arenes by Oxidative Cyclizations of 2,3‐Diarylacrylates

Synthesis of Carboxy‐Functionalized Polycyclic Arenes by Oxidative Cyclizations of 2,3‐Diarylacrylates

Vertically π-expanded coumarin – synthesis via the Scholl reaction and photophysical properties

Stable Ion Studies of the Chrysene Skeleton. Protonation of Chrysene, 6-Halochrysenes, 6-Acetylchrysene, and 4H-Cyclopenta[def]chrysene: NMR Studies of Charge Distribution in Chrysenium Cations and AM1 Calculations

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